Feedback-based display of video, where an image of a user is displayed in real-time, have become increasingly popular in recent years. For example, feedback-based video may be used for video telephony (VT) applications. Video telephony (VT) refers to a system in which users communicate using captured bi-directional video with or without associated audio. Video and/or audio of a first user captured at a first location may be transmitted to a second user at a second location in real or close to real-time, and vice versa. One example of a two-dimensional (2D) video telephony system is the Facetime® video telephony application available for use on the iPhone4® by Apple Inc®. Other examples of 2D VT systems include video chat features such as provided by the Google Talk® web application provided by Google Inc®., and the iChat communication interface provided by Apple Inc®. Many other video telephony applications also exist.
Feedback-based video may also be used for human machine interface (HMI) applications. An HMI application may provide a mechanism for a human user to interface with a computer or other machine. Examples of HMI may include a keyboard, mouse, voice commands, or a touch-screen interface. In recent years, HMI have been developed that utilize some form of motion detection for a machine to receive feedback from a user. Non-limiting examples of motion-based HMI employ various sensors, e.g., one or more accelerometers, gyroscopes, light sensors, or other types of sensors configured to detect user motion. One example of motion-based HMI is employed by the Wii™ gaming console provided by Nintendo Inc®. Another non-limiting example is Microsoft's Kinect® interface for the Xbox® gaming console, which relies on the capture of photographic images of a user to detect user movement for purposes of device input. In some examples, an HMI system may provide for feedback to a user of detected user input (e.g., detected user motion). For example, one or more images of a user may be captured and presented via a display to the user. According to these examples, a user may view his or her movements as the movements are detected. For example, a user may, via image feedback, view himself or herself manipulating virtual objects that are presented via a display. User manipulation of virtual objects may provide machine input.
Three-dimensional (3D) video images, (e.g., for movies, television shows, and the like) have gained in popularity in recent years. For example, technologies have recently been developed (e.g., televisions, 3D glasses, Blu-ray players, gaming systems, computing devices) that allow for users to view 3D video in the home. It may be desirable to provide 3D video for feedback-based display of video, e.g., for video telephony and/or human machine interface mechanisms.
In order to provide images or video perceived as 3D by a user, according to some technologies, images that appear to be captured from slightly different perspectives may be provided to the different eyes of a user. The different perspectives provided to different eyes of the user may create the perception of depth in displayed images. Different images may be presented to each of a user's eyes via specialized glasses that filter one or more images for each eye. In some examples, to provide for 3D image display, images may be captured stereoscopically, e.g., by two or more cameras capturing the same image from different perspectives.